Manufacture of caffein



UNITED STATES PATENT OFFICE.

EASIK LAL DATTA, F CALCUT'IA, INDIA.

MANUFACTURE OF CAFFEIN.

No Drawing.

To all whom it may concern.-

. Be it known that 1, Basil; LAL DATTA. a subject of British India, residing at Caloutta, India, have invented certain new and useful Improvements in the Manufacture of Cafi'ein, of which the following is a specification.

This invention relates to the manufacture I of cafiein from tea.

- The process forming the object of the present invention has for its purpose the ex- 1 traction of cafi'ein from tea waste more alblimin is precipitated.

obtained after filterin of! the preci itates,

cheaply and more readily than by the processes hitherto known.

The extraction of cafi'ein is usually done by treating the aqueous extract of tea with basic or ammoniacal or pure lead acetate or with leady hydroxid to precipitate the tannin and albumin present in the extract. The liquor after filtering OR the precipitate thus obtained is eva orated for the crystallization of caifein. ther methods have also been in use in which the tea extract is eva rated with lime or magnesia and the ry mixture is extracted with chloroform for extracting the cafi'ein contained in it.

According to this invention, the tea extract is recipitated with lime preferably with mil of lime whereby nearly threefourths of the total quantit of tannin and he liquid thus a solution 0 basic albumin oon Specification of Letters Patent.

to only a quarter of what to. completely a PatentedAug. 17, 1920.

Application filed October 17, 1919. Serial No. 331,428.

To carry out my invention to effect, I add milk of lime to a strong aqueous extract of tea when a flocculent precipitate is formed. The addition of milk of lime is continued till the precipitation is complete. The precipitate thus formed is filtered off and the last portions of the mother liquor are secured by means of a filter press. This liquor which contains all the caflein originally present in the tea extract is finally precipitated with a solution of basic lead acetate or pure lead acetate or with lead hydroxid, whenall the tannin and albumin is precipitated. The liquor after finally filtering off the lead precipitate is evaporated to crystallization when pure cafiein crystallizes out.

A typical experiment carried out with extract from 100 grins. of tea gives the followingr results:

otal quantity of lead as lead acetate required to effect complete precipitation of tannin and albumin=15.84 rms.

Total quantity of lead as asic lead acetate requlred to efi'ect the complete precipitation of tannin and albumin after precipi tation with 1ime=4.08fgnn's.; the total quantity of lime required or the above purpose bem 6.51 ms.

at I c aim as m invention and desire to secure by Letters atent is:

As a new recess of manufacture the proces of preclpitationof remaining tannin and albumin from tea extract by means of basic or'simple lead acetate or lead hydroxid after the partial preci itation of tannin and albumin ,b milk of ime for. the production of ca ein.

In testimong whereof I afiix my signature in presence 0 two witnesses.

R'ASIK LAL DATTA. Witnesses.

E. L. Ems, L. ARGHARD. 

